Renal, Electrolyte and Hypertension Division of the Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA.
Nephron. 2018;139(4):293-298. doi: 10.1159/000488501. Epub 2018 Apr 12.
Acid-base disturbances are frequent in critically ill patients. Arterial blood gas (ABG) is the gold standard in the diagnosis of these disturbances, but it is invasive with potential hazards. For patients with a central venous catheter, venous blood gas (VBG) sampling may be an alternative, less-invasive diagnostic tool. However, the accuracy of a central VBG-based acid-base disorder diagnosis compared to an ABG is unknown. The primary objective of this study was to assess the accuracy of a central VBG-based acid-base disorder diagnosis compared to the "gold standard" ABG in critically ill patients.
This was a study of adult patients in a medical intensive care unit that had simultaneously drawn ABG and central VBG samples. Expert acid-base diagnosticians, all nephrologists, diagnosed the acid-base disorder(s) in each blood gas sample. The central VBG diagnostic accuracy was assessed with percent agreement, sensitivity, and specificity compared to the ABG-based diagnosis.
The study involved 23 participants. Overall, the central VBG had 100% sensitivity for metabolic acidosis, metabolic alkalosis, and respiratory acidosis, and lower sensitivity (71%) for respiratory alkalosis, and high percent agreement, ranging from 75 to 94%. VBG-based diagnoses in vasopressor-dependent patients (n = 13, 56.5%) performed similarly to the entire sample.
In critically ill adult patients, central VBG may be used to detect and diagnose acid-base disturbances with reasonable diagnostic accuracy, even in shock states, compared to the ABG. This study supports the use of central VBG for diagnosis of acid-base disturbances in critically ill patients.
酸碱失衡在危重症患者中很常见。动脉血气（ABG）是诊断这些失衡的金标准，但它具有侵入性，且存在潜在风险。对于有中心静脉导管的患者，静脉血气（VBG）采样可能是一种替代的、侵入性较小的诊断工具。然而，中心 VBG 诊断酸碱失衡的准确性与 ABG 相比尚不清楚。本研究的主要目的是评估中心 VBG 诊断酸碱失衡与 ABG 相比的准确性。
这是一项对在重症监护病房同时抽取 ABG 和中心 VBG 样本的成年患者的研究。所有肾病专家在内的专家酸碱诊断医师对每个血气样本中的酸碱失衡进行诊断。与 ABG 诊断相比，评估中心 VBG 的诊断准确性，包括百分比一致性、敏感性和特异性。
研究共纳入 23 名参与者。总体而言，中心 VBG 对代谢性酸中毒、代谢性碱中毒和呼吸性酸中毒的敏感性为 100%，对呼吸性碱中毒的敏感性较低（71%），百分比一致性较高，范围为 75%至 94%。在依赖血管加压素的患者（n = 13，56.5%）中，VBG 诊断与整个样本相似。
在危重症成年患者中，与 ABG 相比，中心 VBG 可用于检测和诊断酸碱失衡，具有合理的诊断准确性，即使在休克状态下也是如此。本研究支持在危重症患者中使用中心 VBG 诊断酸碱失衡。
